Rajat Asthana [off-list ref] wrote:

Syzkaller reported a lockdep warning on non-initialized spinlock:

INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x143/0x1db lib/dump_stack.c:120
 assign_lock_key kernel/locking/lockdep.c:937 [inline]
 register_lock_class+0x1077/0x1180 kernel/locking/lockdep.c:1249
 __lock_acquire+0x102/0x5230 kernel/locking/lockdep.c:4781
 lock_acquire kernel/locking/lockdep.c:5512 [inline]
 lock_acquire+0x19d/0x700 kernel/locking/lockdep.c:5477
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 ath9k_wmi_event_tasklet+0x231/0x3f0 drivers/net/wireless/ath/ath9k/wmi.c:172
 tasklet_action_common.constprop.0+0x201/0x2e0 kernel/softirq.c:784
 __do_softirq+0x1b0/0x944 kernel/softirq.c:559
 run_ksoftirqd kernel/softirq.c:921 [inline]
 run_ksoftirqd+0x21/0x50 kernel/softirq.c:913
 smpboot_thread_fn+0x3ec/0x870 kernel/smpboot.c:165
 kthread+0x38c/0x460 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

We missed a spin_lock_init() in ath9k_wmi_event_tasklet() when the wmi
event is WMI_TXSTATUS_EVENTID. So, add a spin_lock_init() in
ath9k_init_wmi().

Signed-off-by: Rajat Asthana <redacted>
Signed-off-by: Kalle Valo <redacted>

The lock is already initialised in ath9k_init_priv(), so now the same lock is
initialised twice. ath9k_init_wmi() is called before ath9k_init_priv(), so it
looks like we have a race somewhere.

Patch set to Changes Requested.

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20210728192533.18727-1-rajatasthana4@gmail.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches